Finding the Fourth Proportional to 12,839.72, 17,718.56 and 7,174.56

Step by Step Solution

1. Step 1: Write the proportion equation
   12,839.72 : 17,718.56 = 7,174.56 : x
2. Step 2: Convert to fraction form
   12,839.72/17,718.56 = 7,174.56/x
3. Step 3: Cross multiply
   12,839.72x = 17,718.56 × 7,174.56
4. Step 4: Simplify right side
   12,839.72x = 127,122,871.83
5. Step 5: Solve for x
   x = 127,122,871.83/12,839.72
6. Step 6: Final answer
   x = 9,900.75